Docker Notes

To Get a Docker image from the repo (just to download)

docker pull [image]

To List all the downloaded/created images

docker images

To delete a downloaded/created images

Need to delete the container before the image

docker rm [container ID]
docker rmi [image ID]

To Create a Docker Container from an Image

docker run [image]

To Start/Restart a Docker Container

docker start [container ID]

To Stop a Docker Container

docker stop [container ID]

To check docker containers

docker ps

To check all containers (including stopped)

docker ps -a

To get inside the container with bash/sh

docker exec -it [container ID] /bin/bash
docker exec -it [container ID] /bin/sh

To Get Logs of a Docker Container

docker logs [container ID] -f

Docker Network

To have one or more containers in the same network

Listing Network

docker network ls

To Create

docker network create [network-name]

To run mongo and mongo-express in the same network

docker run -d \
-p27017:27017 \
-e MONGO_INITDB_ROOT_USERNAME=admin \
-e MONGO_INITDB_ROOT_PASSWORD=password \
--network mongo-network \
--name mongodb \
-v mongo-data:/data/db \ 
mongo

docker run -it -d --rm \
-p 8081:8081 \ 
-e ME_CONFIG_MONGODB_ADMINUSERNAME=admin \ 
-e ME_CONFIG_MONGODB_ADMINPASSWORD=password  \ 
-e ME_CONFIG_MONGODB_SERVER="mongodb" \  
--network mongo-network \ 
--name mongo-express \ 
mongo-express

Docker Compose

This is to have individual commands setup in a single config file.

Docker Compose takes care of creating a common network!

mongo-docker-compose.yaml

# version of docker-compose
version: '3'
services:
    # container name
    mongodb:
        image: mongo
        ports:
            - 27017:27017
        volumes:
            - mongo-data:/data/db
        environment:
            - MONGO_INITDB_ROOT_USERNAME=admin
            - MONGO_INITDB_ROOT_PASSWORD=password

    mongo-express:
        image: mongo-express
        ports:
            - 8081:8081
        environment:
            - ME_CONFIG_MONGODB_ADMINUSERNAME=admin
            - ME_CONFIG_MONGODB_ADMINPASSWORD=password
            - ME_CONFIG_MONGODB_SERVER=mongodb

# list all the volumes used by all the containers
volumes:
    mongo-data:
        driver: local

How to start / Shutdown Docker Compose

docker-compose -f mongo-docker-compose.yaml up -d

docker-compose -f mongo-docker-compose.yaml down -d

Docker Volume Locations

3 Different types of volumes:

-v host_path:container_path (host volumes)

-v container_path (anonymous volumes)

-v named_path:container_path (named volumes, use in production)

Win  : C:\ProgramData\docker\volumes
Linux: /var/lib/docker/volumes
Mac  : /var/lib/docker/volumes

Docker Commit

Commit is to make a new image from a container

docker commit [container ID] [new image name]

Dockerfile

A blueprint for building images

# start by basing it on another image
FROM node:13-alpine

ENV MONGO_DB_USERNAME=admin \ 
    MONGO_DB_PWD=password

# run will exec a linux command inside the container
# can have many RUN commands
RUN mkdir -p /home/app

# copy command copies from the host to the container
COPY ./app /home/app

# execute node server.js inside the container
# can only have one CMD command, this is the entry point
CMD ["node", "/home/app/server.js"]

How to build a Dockerfile

docker build -t [image name]:[version] [Dockerfile]

E.g. docker build -t my-app:1.0 .

.....
.....
Successfully built 313422855d43  <-- is the image ID
Successfully tagged my-app:1.0

.....
.....
docker run my-app:1.0